Two hundred line connector switch



April 23, 1963 c. E. LOMAX TWO HUNDRED LINE CONNECTOR SWITCH 3 Sheets-Sheet 1 Filed June 24, 1959 i j 3H j A H J Q PBX LINES Fm. 1B

INVENTOR.

Clarence E. Lomox 'fi a AHy.

A ril 23, 1963 c. E. LOMAX 3,

TWO HUNDRED LINE CONNECTOR swrrca Filed June 24, 1959 s Sheets-Sheet 2 FIG. 2

C201 CONNECTOR 200 0201 VERT 255 o 3 O O VERT. BANKS 22o INVENTOR.

C lclrence E. Lomex United States Patent 3 087 023 TWO HUNDRED LnsE eoNNEcroR swrrcn Clarence E. Lomax, Hastings, Nehru, assignor to Automatic Electric Laboratories, Inc, a corporation of Delaare Filed June 24, 1959, Ser. No. 822,666 5 Claims. ((11. 179-48) This invention relates in general to telephone systems, and more particularly to a connector switch having a maximum capacity for two hundred lines of party lines and private branch exchange lines.

In the past, a regular PBX connector consumed one hundred call numbers, and yet served far less than one hundred subscribers, which is a loss of call numbers. For

instance, many small business concerns have only one line and yet they are connected into a PBX connector group because it is expected that they may later need a second line, which results in leaving an unused contact in the PBX connector bank and represents a lost call number.

It is therefore an object of this invention to provide a connector adaptable to changing conditions so that the number of levels for one service can be increased and the levels for the other service decreased.

It is a further object of this invention to provide a connector of the Strowger type which will give automatic trunk selection to a plurality of PBX trunks without the wipers moving beyond the terminals to which they Were dialled.

Another object of this invention resides in a connector with two sets of wipers which move together, one set to select terminals in a first group and the other set to select termnials in a second group, a means whereby the operation of the dial can determine which set of wipers to use and. also select the desired terminal, and a means whereby the connecting together of the two corresponding terminals will result in serving a two-party line and give selective ringing.

Another object of this invention resides in a connector which serves private branch exchanges, which has a plurality of groups of trunks on one or more levels, which has one or more trunks in each group of trunks, and which, when there is more than one trunk in the group called, will automatically select an idle trunk without the switch rotating.

A feature of the present invention resides in the use of 7 vertical banks and auxiliary wipers in the connector which control dropback, wiper selection, and Wanted Tone, all dependent on the vertical bank level to which the auxiliary wiper is stepped and the sequential order in which the corresponding digit was received.

Another feature of the invention resides in applying a Wanted Tone momentarily to a busy line for notification to the party thereat that someone is trying to call.

Other objects and features will become apparent from a perusal of the following specification taken in combination with the drawings, of which:

FIGS. 1A and 1B are schematic circuit drawings representing two different levels of bank contacts on a connector, and more specifically FIG. 1A shows a twoparty line, and FIG. 1B shows PBX lines and trunks; and

FIGS. 2 and 3, with FIG. 3 to the right, shows a two hundred line capacity connector switch of the Strowger type.

With the utilization of a double wiper set in a connector, a two-party line can be conjointly engaged byboth wiper sets simultaneously. Likewise, two trunks to .the

same PBX can also be conjointly engaged by both wiper sets. In the case of the two-party lines, a prefix digit to be absorbed acts as the means through a vertical bank to determine which wiper set will be utilized for extending 'ice nected to the same PBX line but to a different PBX trunk.

If the first wiper set engages a busy trunk, a wiper switchingrelay is operated to disable the first Wiper set and en- 'ables the second wiper set to test its associated PBX trunk withoutrotation of the wipers. Only when both PBX trunks extending to a particular PBX line are busy will a busy tone be transmittedto a calling party.

Referring briefly to FIGS. 1A and 1B showing two separate double levels of bank contacts, a preferred gen eral layout of the different levels will be described. The first five double levels will be utilized for a single or twoparty line, as shown by the two-party line L in FIG. 1A. The last five double levels will be utilized for PBX trunks, as shown by the sixth level in FIG. 1B. As shown for the two-party line L100 of FIG. 1A, it will be seen that a first set of wiper level bank contacts corresponding to the first party thereon is multiplied .to a second set of wiper level bank contacts corresponding to the second party, also thereon. These wiper level contact banks for two-party lines are on the same vertical levels,

but are accessed by two different sets of wipers, 391-393 or 394-396. As shown on line L100 a ringer R1 for subscriber X112 is connected to the negative side of the line and ringer R2 for subscriber X212 is connected to the positive side of the line, and thus either the wiper 391 or and X2712 are shown as a two-party line, they could easily be changed to single party lines by removing the multiple connections across the band contacts, such as shown in set of wipers, connector 200 will substitute switch con nection to the second set of wipers to extend a testing connection to line 2.

Referring briefly to FIGS. 2 and 3, the connector 200 I comprises fourteen relays, three magnets, two sets of wipers, as fell as a pair of auxiliary wipers. The vertical banks 220 are. divided into a left and right set of banks having separate wipers 221 and 222 respectively. The vertical banks are so wired that if a first digit 1 is received over the calling loop, the wipers will restore, and if a firstdigit 2 is received the .Wipers will restore and switch from wiper set 391-393 to wiper set 394-396. If the digit 1 or 2 is dialled as a second digit following their usage as a first digit, the wipers will not restore and the first and second levels can thus be used for extending calls. Therefore, the first digit will determine which set of wipers will be used for party line calls providing the second digit is a digit from 1 to 5 snce only the first five levels are reserved for party lines.

Since the upper five levels are reserved fior PBX trunks, no prefix digit (1 or "2) will be necessary. The level dialled to on the first digit received will be the level used, with directive dial rotary action taking place in the usual manner and always utilizing the wipers such as 391-393. If the PBX trunk tests busy, busy test relay 330 will operate when slow-to-release relay 340 restores which causes wiper switch relay 380 to operate by way of the right vertical bank. Relay 380 thus substitutes the Patented Apr. 23, 1963 upper wipers 391-393 with the lower wipers 394-396 without additional stepping of the wipers to thus test the busy condition of a second trunk extending to the same PBX. If this second trunk also tests busy, the busy test relay 330 remains operated and a Wanted Tone will be momentarily transmitted over this second trunk to'notify the busy party thereat of an awaiting call.

An alternate wiring-scheme comprising X and Y wiring is utilized for extending a Wanted 'Ione to busy lines for notification of an awaiting call. By utilizing the X wiring which is strapped to the upper five left bank contacts on vertical banks 220', only PBX subscribers will receive this Wanted Tone in the event both of their respective lines are found busy. By utilizing the Y wiring, both PBX lines and single or two-party lines will receive this Wanted Tone on busy lines. These operations will become more clearly understood from the detailed operation to follow.

Operation Assuming that a call is being made tosubstation X112 (FIG. 1A), connector 200 is found idle by a preceding selector switch (not shown) encountering battery, which may be traced as extending from the upper winding of relay 260, contacts 251 and back over control conductor C203 to initiate a seizure of this connector in a wellknown manner. Thereupon, the loop circuit is extended over negative conductor C201, contacts 211 and upper Winding of relay 230' to battery on the one hand, and over positive conductor C202, contacts 213, and lower winding of relay 230 to ground on the other hand. Relay 230 operates and closes an obvious circuit at contacts 231 to' relay 2.40. Relay 240 operates, closing ground at contacts 241 over conductor C301 through the upper winding of relay 360, contacts 385, and to control wiper 393. Contacts 2'42 close ground to operate relay 260 and extend it back over control conductor C203 to hold the preceding equipment in a well known manner. At contacts 243 and the operation of relay 260 at contacts 261, a circuit is prepared to the lower winding of relay 260 and vertical magnet 255. Contacts 245 close ground to certain contacts on the left and right bank contacts of vertical bank 220; and prepares circuits to relays 27 0, 280, 360, and 280.

Referring briefly to FIG. 1A, as previously mentioned, substation X112 has its ringer on the negative side of the line and must therefore be rung over wiper 39 1. Thus, the digits 112 must be dialled as the last three digits by the calling party in order, to ring this substation. Upon receipt of'the first digit 1, pulsing relay 230 will intermittently restore and operate onetime. Contacts 231 will open the circuit to relay 240 however, relay 240 is of the sloW-to-releas'e type and remains operated during the duration of dialling. Contacts 232 intermittently closes ground, via contacts 243', 261, to the lower winding of relay 260 to battery, and through the winding of the vertical magnet 255 to battery. The vertical magnet 255- energizes to step the wipers 391-396 to the first level of bank contacts, and also step the auxiliary. Wipers 221 and 222 to their respective bank contacts on vertical banks 220. Upon the wipers taking their first step, the VON springs operate, closing at VON contacts 256 an obvious circuit to relay 250. Relay 250* operates, and at contacts 251 opens the operating circuit to relay 260 however, relay 260 being of the slow-to-re'lease type remains operated during pulsing through its lower winding. At contacts 252, a circuit is prepared to the release magnet 370. Contacts 25 3' close a shunt across the lower winding, of relay 270. Upon the termination of the digital impulse series, the slow-to-release relay 260 restores, and at' contacts 263 closes a circuit to relay 280; the circuit extending from battery, winding of relay 280, contacts 282, 273-, conductor C305, first left contact and wiper 221 on the vertical bank 220,v conductor C205 contacts 263, conductor'C204, to ground at contacts 245. Relay 280 operates, closing its make contacts 283 to close a lockirig circuit for itself via grounded conductor C204, before opening its original operating circuit at contacts 282. Contacts 281 close ground via contact 253, 272, conductor C303, contacts 266 to energize release magnet 370. The release magnet 370 in energizing restores the wipers to normal and opens the VON contacts 256 to restore relay 250. Relay 250 in restoring opens the shunt across the lower Winding of relay 270 by opening contacts 253. Relay 270 thereupon, operates in series through its lower winding with the release magnet 370. Relay 270 in operating closes its X contacts 271 first, to lock relay 270 operated through its upper Winding via grounded conductor C204. Relay 270 thereafter opens contacts 273 and 274 without effect at this time, except that in opening contacts 274, the wiper switching relay 380 will be unable to operate on the next digit to switch wipers. Contacts 272 open the circuit to release magnet 370 to cause deenergization thereof.

Upon receipt of the second digit 1, line relay 230 will again release and operate one time to pulse vertical magnet 255 to step the wipers 391-396 and 221-222 to their respective first bank contacts, as above described. However, in this case, when the VON contacts 256 close to operate relay 250*, the closing of contacts 253' to shunt relay 270 is ineffective since relay 270' is locked operated through its upper winding. Also, the circuit to release magnet 370is opened at contacts 272. After a short duration, the slow-to-release relay 260 restores after termination of the second dialled digit, and at contacts 262 prepares a circuit to the rotary magnet 325.

Upon receipt of the third or last digit 2,'line relay 230 will intermittently release and operate two times. Upon each intermittent release of relay 230, a ground pulse is. closed via contacts 232, 243, 262, conductor C36 2, contacts 335, 365, winding of rotary magnet 325 to battery, to thus pulse rotary magnet 325 two times. Also, this ground pulse will 'go through the winding of relay 340 to cause operation thereof, and being of the sloW-to-release type will remain operated throughout the impulse series. At contacts 341, an obvious alternate circuit is closed to the rotary magnet 325, so that in case a busy contact is engaged during rotation of the wipers, the momentary operation of busy test relay 330 Will not interfere with direct rotary dialling by opening contacts 335. At contacts 342an obvious circuit is closed to relay 350. Relay 350 operates, and at contacts 351 opens a prepared circuit for transmitting a Wanted Tone over the positive wiper 392 Contacts 352 open a prepared Busy Tone circuit to the calling party. At contacts 353 a prepared circuit to relay 360 is opened, and at contacts 354 the busy test relay 330 is connected to the control wiper 393 via contacts 385. At contacts 356 a circuit is prepared to relay 320, which will be explained shortly hereafter. After the termination of the two impulses, rotary magnet 325 will have stepped the wipers 391396 to their respective second rotary position on the first level of bank contacts.

As above mentioned, the operation of relay 350 closes contacts 356 to prepare a circuit to relay 320. We will assume first the utilization of the X Wiring. Since in this case the X wiring is connected from the sixth to tenth bank contacts on the left vertical bank of 220, and the wiper 221 is on the first bank contacts, relay 320 will not be affected. As mentioned, these upper two banks correspond to the PBX lines and therefore the Wanted Tone as normally extended by relay 320 is not utilized on calls to party lines. However, if the Y wiring is used, every time contacts 356 close, a direct ground circuit is closed to relay 320. As mentioned, the Y wiring is used when it is desired to provide Wanted Tone to all types of lines. The operation of relay 320 closes contacts 321 to prepare for the extension of Wanted Tone to the called party in the event this line is found busy.

Returning to the rotary stepping of wipers 391-396 to the second rotary bank contacts, and if it' is assumed that the called substation X112 is busy, busying ground is encountered by the control wiper 393 in a well-known manner. The busy test relay 330 will operate from this ground via contacts 385 and 354. The slow-to-release relay 340 will release a short period after the termination of the rotary impulse series, opening at contacts 342 the circuit to the slow-to-release relay 350. The closing of contacts 343 and the operation of relay 330 at contacts 336 closes ground to the upper right five bank contacts on vertical bank 220 without effect, however, on this call. After a short duration, the slowto-release relay 350 restores, closing make contacts 355 before opening contacts 354 in the operating circuit for the relay 330 to close a locking circuit to relay 330'. This last-mentioned locking circuit extends from battery, the winding of relay 330, contacts 355, 334 and 241 to ground. Assuming that the Y wire is used whereby relay 320 operates, the Wanted Tone is extended to the called line via contacts 321, 331, 351, 383, wiper 392 and over the positive side of the line L100 to notify the called party X112 that another party is trying to call him. Also, a Busy Tone is sent back to the calling part via contacts 352, 332 and back over positive conductor C202 At contacts 335- the circuit to relay 340 is further opened. The above-mentioned Wanted Tone would remain on the line called only the length of time it" takes for the slow-to-release relay 320 to restore as a resultof its operating circuit being opened at contacts 356 when relay 350 restored. The called line, having received the Wanted Tone, may then proceed to hang up at his discretion, and attempt to make. his line idle to await the return of the call. The calling party, upon receipt of the Busy Tone, would proceed to hang up to release the connection, and remake the call at a later time at his discretion.

Assuming however that the called party X112 is idle, battery will be encountered by control Wiper 393, and the busy test relay will not operate. After a short duration, the release of the slow-to-release relays 340 and 350 completes a circuit to the switch-through relay 360 from the battery encounter-ed by wiper 393, contacts 385, 353, upper winding of relay 360, contacts 333, conductor C301, and contacts 241 to ground. Relay 360 operates, closing its X. contacts 367 first, to close a locking circuit for itself through its lower winding from ground at contacts 245 and via conductor C204. Thereafter, relay 360 operates its remaining contacts closing at contacts 362 the ringing frequency to the called party via GEN, the lower winding of relay 310, contacts 311, 362, 381,- wiper 391 and to the ringer R1 of subscriber X112 connected to the negative side of the line. Contacts 361 extends ringback tone via contacts 313 and negative conductor C201 to the calling party. At contacts 363 a circuit is prepared to ringing relay 310. At contacts 364 a lockingcircuit is prepared to ringing relay 310. At contacts 365 and 366 prepared circuits are further opened to relay 340 and releasemagnet 370 respectively.

When the called party answers, the ringer resistance is removed from across the line and the called partys loop is closed to operate the ringing relay 310 via battery on GEN lead, the lower winding of relay 310, contacts 311, 362, 381, wiper 391, through the called partys loop, wiper 392, contacts 383, 363, 314 to ground. Relay.310i closes its X contacts 316 first to lock itself operated through its upper winding via ground at contacts 364, Thereafter, the remaining contacts of relay 310 operate, opening at contacts 311 and 314 the abovetraced ringing circuit and the operating circuit for relay 310. At contacts 313 ringback tone is removed 'from the calling line. At contacts 312 and 315 the talking circuit is extended to thecalled party, while a circuit is alsoclosed to relay 210, with this circuit extending from battery, upper winding of relay 210, conductor C201, contacts 312, 362, 381, wiper 391, through the loop of called party X112, wiper 392, contacts 383, 363, 315, conductor C202 and the lower winding of relay 210 to ground. Relay 210 operates, closing contacts 212 and 214 to reverse polarity on the calling loop from relay 230 while maintaining this relay operated during the opening of contacts 211 and 213. This reversal in polarity will operate the meters on the line (not shown) in a well-known manner. At contacts 215 a second ground is applied to conductor C204 to aid in maintaining relay 380 operated. Relay 210 will thus provide transmission battery for the called party, and relay 230 will provide transmission battery for the calling party.

Assume next a call to the second substation X212 on line L100. In this case the digits 212 must be dialled into connector 200. Upon receipt of the first digit 2, line relay 230 will pulse the vertical magnet 255 in a manner previously described and step the wipers to their respective second level of bank contacts. The restoring of relay 260 at the termination of the first impulse series will operate relay 380 instead of relay 280 in this case. This last circuit extending from battery, the winding of relay 380, contacts 388, conductor C306, contacts 274,

conductor C206, the second left bank contact on vertical bank 220, wiper 221, conductor C205 contacts 263 and 245 to ground. Relay 380 operates, closing contacts 382, 384 and 386 to switch the circuit connections fromthe first set of wipers 391-393 to the second set of wipers 394396. At contacts 389 relay 380- locks operated to grounded conductor C204. At contacts 387 a circuit is closed to relay 280; the circuit extending from battery, the winding of relay 280, contacts 282, 273, conductor C305, contacts 387, conductor C308, second right bank contact on vertical bank 220, wiper 222, conductor C204, to ground at contacts 245. Relay 280 operates, locks via contacts 283 to grounded conductor C204, and closes the previously traced circuit to the release magnet 370 at contacts 281. The release magnet 370 thereafter operates to return the wipers to normal. Relay 250 will restore to in turn operate and lock relay 270 operated.

as previously described.

The receipt of the last two digits 12 operates the.

connector to step and rotate the wipers in a manner previously described to seize line L with the exception that relay 380 has switched connections to use the second set of wipers. In this case the ringing frequency will be transmitted over wiper 394, and as shown in FIG. 1A, the bank contacts accessible by wiper 394 are strapped to the positive side of the line and ringer R2 will thus respond to notify substation X212 of an incoming call. should this party be busy at the time the wipers engaged the line, the momentary Wanted Tone would be transmitted over wiper 395 to the negative side of the line.

Thus on calls to either party on the line the Wanted Tone and ringing frequency are always transmitted on opposite sides of the line.

Although only a two-party line L100 has been shown, it should be understood that substations X112 and X212 could easily be converted to single party lines. Also, each level of bank contacts could contain mixed lines of single and two-party lines as the subscribers may so desire, or be easily convertible to one or the other by merely changing the strapping on the bank contacts. Furthermore, it is to be pointed out that the vertical banks 220 are effective only on the first digit dialled into connector 200, and therefore calls to levels 2-5 on the second digit would cause the same respondence as above described for the first level.

Release I On the termination of a call, when the called party hangs up, the loop circuit to relay 210 is opened to cause restoration thereof. The restoration of relay 210' at contacts 211 and 213 again reverses polarity to the calling loop via relay 230 to again operate the meters (not shown) to meter the call. At contacts 215 one of the grounds is removed from conductor C204.

Also, i

When the calling party hangs up, the loop circuit to relay 230' is openedcausing restoration thereof; At contacts 231 the circuit to the slow-to-release relay 240 is opened. At contacts 232' a circuit is prepared to the release magnet 370'. After a short duration the slow-torelease relay 240' restores, opening at contacts 245 the circuits to relays 270, 280, 360, and 380 to cause restoration thereof, to close a circuit to the release magnet 370, via battery, the release magnet 370, contacts 366, conductor C303, contacts 252, 244- and 232. to ground. The release magnet 370 will thus energize to restore the wipers to normal to in turn open VON contacts 256 to restore relay 250 tacts-252-to deenergize the release magnet 3701 Also, the restoration of relay 3:60 at contacts 364 will open the lock circuit to relay 310 to cause its release.

PBX Call As previously mentioned it was assumed that the sixth to tenth levels ofv connector 200 were reserved-for PBX lines. Therefore, the first digit dialled must be from 6 to 0.

Referring briefly to FIG. 1B showing the PBX trunks 50 and 60 accessible from the sixth level and first bank contacts, a call to these trunks Will be described. The first two digits dialled into connector 200 must thus be the digits 61.

Upon receipt of the first digit. 6, line relay 230 will pulse the vertical magnet 255- six times to step the wipers to the sixth level of bank contacts in a manner previously described. At thetermination of the received first digital impulse series, relays 230, 240, and 250 are operated and after a short duration, relay 260 has released in a manner previously described. By these operations, ground has been placed;on the X wiring (assuming that this wiring is used), from ground, contacts 245, conductor C204, contacts 263, conductor C205, wiper 22d, sixth left bank contacts of vertical banks 220. The release of relay 260' at contacts 262 now prepares a circuit to rotary magnet 325.

Upon receipt of the second dialled digit 1, line relay" 230 will intermittently restore to close a circuit to the rotary magnet 325 over a circuit from ground, contacts. 232, 243, 262, conductor C302, contacts 335, 365, winding of the rotary magnet 325 to battery. The rotary magnet 325 will thus energize to rotate the wipers 391-396 to their respective first rotary bank contacts. Over the above-mentioned rotary circuit, the slow-to-release relay 340 also operates, closing at contacts 341 an alternate path for itself and the rotary magnet 325. At contacts 342 an obvious circuit to relay 350 is closed. Relay 350 operates, opening points at contacts 351 and 352 in the prepared circuits for Wanted Tone and Busy Tone respectively. At contacts 354 busy test circuit for busy relay 330 is closed from control wiper 393 of the first set of wipers. Also, assuming for the present that'the X wiring isbeing used, at contacts 356 the ground on the X wiring is closed to slow-to-release relay 320 Relay 3201 will thus operate closing contacts 321 to prepare a point in the application of the Wanted Tone to the called line. Assuming the use of Y wiring containing the permanent ground, relay 320 would operate as previously described.v At the termination of this last digital impulse series, the wipers will be engaged with their respective first bank contacts on the sixth level, and the circuits to the rotary magnet 325 and relay 340 will be opened at contacts 232. Relay 340 subsequently restores its contacts tonormal after a slow-to-release interval of time.

Assuming first that line 1 corresponding to PBX trunk 50, is found busy, ground will be encountered in the usual manner by control Wiper 393, which will cause the busy test relay 330 to operate. Relay 3 50, being slow-to-release, will permit relay 330- to' close at contacts 336 a circuit to relay 380 before relay 350 restores. This last circuit extending from battery, winding of relay 380,

Relay 250 in restoring opens concontacts 388, conductor C306, contacts 274, conductor C206, the tenth to sixthright bank contacts of vertical bank 220, wiper 222, conductor C304, contacts 336, 343 to ground. Relay. 380'thus operates before the slow-torelease relay. 350 restores, and at contacts 389* relay 380 locks operated to grounded conductor C204. Relay 380 at contacts 382, 384 and 386 switches the connection of connector 200 to the second set of wipers to test the line 2 corresponding to PBX trunk 60. Since relay 380 operates before relay 350- restores, the Wanted Tone is never transmitted over linel, nor is a Busy Tone transmitted back to the calling party as aresult of this line testing busy. Control wiper 396 now engages the contacts corresponding to line 2 (FIG. 1B), and the idle or busy condition existing thereon will determine whether or not relay 330 will remain operated; Should line 2 also be busy, wiper 396will encounter busying ground and relay 330 will be maintained operated. However, should line 2 be idle, relay 330' will restore.

Assuming line 2 is also busy, relay 330 is maintained operated, whereby slow-to-release relay 350 eventually restores, and Wanted Tone is extended over line 2 via contacts 321, 331, 351, 384, wiper 395, the positive side of the line and via PBX trunk 60 to a PBX'subscriber. At contacts 352 Busy Tone is closed tothe calling party, and at contacts 355 relay 3'30 locks operated, all as previously described. Thus, the called P-BlX subscriber, having received the Wanted Tone over line 2, may attempt to make one of 'his lines idle in anticipation that the calling party will call again. The callingparty upon receipt of the Busy Tone will hang up. and call again at alater time.

Assuming however that line 2 was found to be idle, the control wiper 396 therefore encounters battery, and busy test relay 330 will restore. After a short duration the sloW-to-release relay 350 will restore to close a circuit to the switch-through relay 360; the circuit extending from battery engaged by control wiper 396, contacts 386,

353, upper winding of relay 360, contacts 333, conductor- C301, and contacts 241 to ground. Relay 360* operates, closing its X contacts 367 first to lock relay 360 operated through its lower winding via grounded conductor C204. Thereafter, relay 360 closes the ringing frequency to the called line and returns ringback tone in a manner previously described.

It is is assumed that When the call was originated, line 1 had been found idle, busy test relay 330' wouldnot have operated. In thiscase, the call would have been extended over the first set of wipers in a manner previously described, utilizing line 1. and PBX trunk 50;.

We have thus described av connector which will determine Which set of wipers will be utilized by the receipt of a first predetermined digit on a first type of call, and will switch wipers when a first line is busy, without any automatic rotation thereof on a second type of call.

a For night service, and also for special calls during the day, it may be desirable to eliminate the automatic trunk selection so' that only the Wantedline of the two lines will be called. This can be done by'prefixing the digit 1 or 2 to the connector call number.. The prefix digit 1 operates relay 270 so that relay 380 cannot operate even though the upper line is busy as previously described. The prefix digit 2 would also operate relay 270- but, in addition, it operates relay 380 so that only the lower line is called. It will thus be seen from the preceding description that this switch could have only thev What is claimed is:

1. In a telephone system, a calling station, a connector switch of the two motion type, means for extending a connection from said calling station to said connector switch, a plurality of private branch exchanges, a plurality of two-party lines, a first plurality of levels of bank contacts on said connector terminating connections with each party of each said two-party-lines, a pair of lines individually to each private branch exchange, a second plurality of levels of bank contacts terminating connections with each line of each said pairs, a first and a second set of wipers in said connector with each wiper set constituting one of the two means of access to each two-party line and to each private branch exchange, stepping means operated for stepping said two sets of wipers simultaneously in a primary and then a secondary motion in response to a first and second series of digital impulses received over said connection, testing means for testing the busy or idle condition of a called two-party line in one case and for testing the busy or idle condition of said lines of said pair individual to a called private branch exchange in another case, means operated in response to said wipers stepping into engagement with selected bank contacts in said first plurality of levels in accordance with said primary and said secondary movements for connecting said testing means to test the selected two-part line to determine the busy or idle condition of only one party thereon, and means operated in response to said wipers stepping into engagement with selected bank contacts in said second plurality of levels in accordance with said primary and said secondary movements for connecting said testing means to test the busy or idle condition of said second line of said pair individual to the selected private branch exchange in response to the first line of said pair being busy.

2. In a telephone system wherein means at a calling station is operated to transmit impulses corresponding to dialed digits over a connection comprising a switch train to directively control a connector switch in'successive primary and secondary movements, the combination therewith of a plurality of two-party lines, a first and a second set of wipers in said connector switch, stepping means in said connector switch operated in response to receipt of impulses corresponding to a first dialed prefix digit for simultaneously stepping said wiper sets only in said primary movement, wiper set selecting means normally routing connections from said connector to said first wiper set, means for operating said Wiper set selecting means only in response to said prefix digit being a certain predetermined numerical value for routing said connections from said connector to said second wiper set, wiper release means, means operated in reponse to the termination of said prefix digit impulses for operating said wiper release means to restore said wiper sets to normal, connector terminals accessible by said wiper sets and individually terminating each party of each of said two-party lines, said stepping means reoperated in response to receipt of impulses corresponding to the dialing of two digits following said prefix digit for simultaneously stepping both said wiper sets in said primary and said secondary motion successively to simultaneously engage said terminals terminating both said parties on a called two-party line corresponding to said dialed two digits, a signal source in said connector, and means for extending the signal from said source to signal a particular one of said parties on said called two-party line over one of said wiper sets selected for use by said wiper set selecting means in accordance with said numerical value of said dialed prefix digit.

3. In a telephone system, a calling station, a connector switch of the two motion type, means for extending a connection from said calling station to said connector switch, a private branch exchange, a first and second set of wipers in said connector switch, a first set of terminals accessible by only said first set of wipers, a first path terminating a saidsecond set of terminals, stepping means operated in response to receipt of a first and a second series of digital impulses over said connection for simultaneously stepping both said wiper sets in a primary motion and thereafter in a secondary motion into respective engagement with said first and said second set of terminals, testing means operated subsequent to the termination of said wiper stepping for testing the busy or idle condition of said first path connection with said private branch exchange over said first set of terminals, means operated in response to a busy condition existing on said first path for connecting said testing means to test the busy or idle condition of said second path connection with said private branch exchange over said second set of terminals without additionally stepping said Wipers, a source of wanted tone, and means operated by said testing means in response to a busy condition existing on said second path for momentarily connecting said source of wanted tone to said second path for informing said private branch exchange of an awaiting call.

4. In a telephone system, a calling station, a connector switch of the two motion type, means for extending a connection from said calling station to said connector switch, a private branch exchange, a first and second set of wipers in said connector switch, stepping means for stepping said two sets of wipers simultaneously in a primary and then a secondary motion in response to a first and second series of digital impulses received over said connection, a pair of auxiliary wipers in said connector switch stepped simultaneously in only said primary motion with said first and second sets of wipers, a first setof terminals accessible by only said first set of wipers for extending a connection to said private branch exchange over a first path, a second set of terminals accessible by only said second set of wipers for extending a connection to said private branch exchange over a second path, testing means connected with said first set of wipers and operated subsequent to said wiper stepping for testing the busy or idle condition of said first path connection with said private branch exchange over said first set of terminals, and wiper selecting means operated by said auxiliary wipers in response to a busy condition existing on said first path for connecting said testing means with said second set of wipers to test the busy or idle condition of said second path connection with said private branch exchange over said second set of terminals without further stepping said Wipers.

5. In a telephone system, a calling station, a connector switch of the two motion type, means for extending a connection from said calling station to said connector switch, a private branch exchange, a first and second set of wipers in said connector switch, stepping means for stepping said two sets of wipers in simultaneously in a primary and then a secondary motion in response to a first and second series of digital impulses received over said connection, a pair of auxiliary wipers in said connector switch stepped simultaneously in a primary motion with said sets of wipers, a wiper switching relay, a first set of terminals accessible by only said first set of wipers for extending a connection to said private branch exchange over a first path, a second set of terminals accessible by only said second set of wipers tor extending a connection to said private branch exchange over a second path, testing means connected with said first wiper set and operated subsequent to said wiper stepping for testing the busy or idle condition of said first path connection with said private branch exchange over said first set of terminals, circuit means prepared by said primary motion of said auxiliary wipers to said wiper switching relay, means operated by said testing means in response to a busy condition existing on said first path for completing said cir- 1 1 cui-t means to operate said wiper switching relay, and means operated by said Wiper switching relay for disconmeeting said testing means from said first setofwipers and connecting said'testi'ng means to said second set of wipers, whereby-the busy. or idlecondition of said second path connection withsaid private branch exchange is tested over said second'set of terminals without further stepping said wipers.

References Cited in the file of this patent UNITED" STATES PATENTS W-icks July 19, 1927 Dixon July 20, 1937 West et a1. Apr. 7, 1942, Ostline Apr. 22, 1947 Corbett May 30, 1950 Bakker May 7, 1957 

1. IN A TELEPHONE SYSTEM, A CALLING STATION, A CONNECTOR SWITCH OF THE TWO MOTION TYPE, MEANS FOR EXTENDING A CONNECTION FROM SAID CALLING STATION TO SAID CONNECTOR SWITCH, A PLURALITY OF PRIVATE BRANCH EXCHANGES, A PLURALITY OF TWO-PARTY LINES, A FIRST PLURALITY OF LEVELS OF BANK CONTACTS ON SAID CONNECTOR TERMINATING CONNECTIONS WITH EACH PARTY OF EACH SAID TWO-PARTY LINES, A PAIR OF LINES INDIVIDUALLY TO EACH PRIVATE BRANCH EXCHANGE, A SECOND PLURALITY OF LEVELS OF BANK CONTACTS TERMINATING CONNECTIONS WITH EACH LINE OF EACH SAID PAIRS, A FIRST AND A SECOND SET OF WIPERS IN SAID CONNECTOR WITH EACH WIPER SET CONSTITUTING ONE OF THE TWO MEANS OF ACCESS TO EACH TWO-PARTY LINE AND TO EACH PRIVATE BRANCH EXCHANGE, STEPPING MEANS OPERATED FOR STEPPING SAID TWO SETS OF WIPERS SIMULTANEOUSLY IN A PRIMARY AND THEN A SECONDARY MOTION IN RESPONSE TO A FIRST AND SECOND SERIES OF DIGITAL IMPULSES RECEIVED OVER SAID CONNECTION, TESTING MEANS FOR TESTING THE BUSY OR IDLE CONDITION OF A CALLED TWO-PARTY LINE IN ONE CASE AND FOR TESTING THE BUSY OR IDLE CONDITION OF SAID LINES OF SAID PAIR INDIVIDUAL TO A CALLED PRIVATE BRANCH EXCHANGE IN ANOTHER CASE, MEANS OPERATED IN RESPONSE TO SAID WIPERS STEPPING INTO ENGAGEMENT WITH SELECTED BANK CONTACTS IN SAID FIRST PLURALITY OF LEVELS IN ACCORDANCE WITH SAID PRIMARY AND SAID SECONDARY MOVEMENTS FOR CONNECTING SAID TESTING MEANS TO TEST THE SELECTED TWO-PART LINE TO DETERMINE THE BUSY OR IDLE CONDITION OF ONLY ONE PARTY THEREON, AND MEANS OPERATED IN RESPONSE TO SAID WIPERS STEPPING INTO ENGAGEMENT WITH SELECTED BANK CONTACTS IN SAID SECOND PLURALITY OF LEVELS IN ACCORDANCE WITH SAID PRIMARY AND SAID SECONDARY MOVEMENTS FOR CONNECTING SAID TESTING MEANS TO TEST THE BUSY OR IDLE CONDITION OF SAID SECOND LINE OF SAID PAIR INDIVIDUAL TO THE SELECTED PRIVATE BRANCH EXCHANGE IN RESPONSE TO THE FIRST LINE OF SAID PAIR BEING BUSY. 